The 39-year-old, Russia's flagbearer at the Games opening ceremony, proved uncatchable on home ice and sealed victory with two more solid runs in front of an exuberant crowd at the Sanki Sliding Centre whose chants of 'ROSSIYA' echoed down the valley.
Pushed by formidable brakeman and Sochi native Alexey Voevoda, a former arm wrestling world champion, Zubkov extended his first-day lead to half a second with a track record 56.08 seconds on his third run and was quickest of all again on his final slide.
The podium placings remained as they had overnight, Zubkov prevailing by an impressive 0.66 seconds with Switzerland's Beat Hefti taking silver and Steve Holcomb of the United States in bronze.
"It's very different when you have to compete for two days - I had a night full of dreams, worries and anticipation," Zubkov said. "I tried to relax. We had some very strong contenders but we have proven we are Olympic champions.
"It's everybody's victory - coaches, technicians and fans. We did our job in the race without thinking about the competitors."
Zubkov briefly entered politics after winning a bronze with Voevoda, 33, in Vancouver four years ago, before returning to the sport in a bid to win gold at his home Games.
The pair also won Olympic silver in Russia's four-man sled in 2006.
Zubkov becomes the third oldest pilot to win the event - behind American Hubert Stevens, who won two-man gold at 41 in Lake Placid in 1932, and Italian Eugenio Monti, who was 40 when he triumphed in Grenoble in 1968.
Hefti, 36, added another medal to his Winter Games collection having won a four-man and two two-man bronzes, while Holcomb, pushed by Steve Langton, earned a first U.S. Olympic medal in the two-man since 1952.
The American scraped onto the podium by the skin of their teeth, edging out the RUS-2 sled of Alexander Kasjanov and Maxim Belugin by three hundredths of a second.
"I hurt my calf last night. But we just kept on fighting. It came down to this - I pushed as hard as I possibly could," said Holcomb, who will defend his Vancouver four-man title later this week.
"When we do well in two-man, we typically do well in four-man. We build momentum."